ML20052F768
| ML20052F768 | |
| Person / Time | |
|---|---|
| Site: | Zimmer |
| Issue date: | 05/05/1982 |
| From: | Youngblood B Office of Nuclear Reactor Regulation |
| To: | Borgmann E CINCINNATI GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8205130596 | |
| Download: ML20052F768 (3) | |
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PDR MService LPDR IPel tier NSIC MAY 5 1982 DEisenhut TIC SHanauer ACRS (16)
RMattson Docket No.: 50-358 HThompson 9
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Mr. Earl A. Borgmann OELD
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Vice President, Engineering OIE ff REC 5iVED The Cincinnati Gas & Electric Conpany TSpeis 2
MAY 101982> 1 P. O. Box 960 DZiemann L-n unamw etc.a -
Cincinnati, Ohio 45201 WHodges u* alp a f
JClifford 9
Dear Mr. Borgmann:
DMcDonald d/
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Subject:
Errors in BWR Water Level Indication By menorandun dated February 9,1982, we transmitted to the Atonic Safety and Licensing Boards for six BWRs, including Zimer, the staff's evaluation to date of the subject natter. This evaluation was initiated to investigate errors in indicated water level at Pil rim 1 during a routine reactor shut-l down and depressurization with dryuell air temperature at 240*F. Large oscillations of the level instrument were attributed to flashing of water in the level instrument lines when reactor water pressure was decreased below saturation pressure at 240*F. High drywell temperature may result from faulty or inoperable drywell coolers and from high energy line leaks or breaks in the drywell. This evaluation was transnitted to you by copy of the February 9, 1982 transmittal to the ASLB.
Based on its evaluation, the staff has concluded that current emergency operating procedure guidelines (NEDO-24934, January 1981) are not adequate for operators to recognize and cope with unreliable reactor water level indications caused by water flashing in instrument lines under all potential abnormal operating and accident conditions. For example, the guidelines recomend depressurization and refill of the reactor if vessel level cannot be detemined. However, the guidelines do not provide an adequate nethod for operators to recognize false high water level indications. Further, based on an audit of procedures for two operating plants, we find that even those portions of the guidelines which provide acceptable steps for coping with water level errors have not been incor-porated into plant procedures.
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The staff's recommendations for resolution of this problem are contained in its l
evaluation that was transmitted to you on February 9,1982. As a first step in i
the resolution, staff recommends the performance of plant specific analyses i
of the susceptibility of reactor vessel water level instrumentation to flashing.
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The magnitude of the error due to flashing depends on the type of instrument i
(whether the reference leg is heated or cold) and changes of elevation of the l
instrument line inside the drywell. Accordingly, please amend your application to provide:
l 8205130596 820505
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Mr. Earl A. Borgmann MAY 5 1932 (1) A description of the Zimmer reactor vessel water level instruments, including the types of instruments and instrunent line elevation changes inside the dry-well.
(2) The results of an analysis of the magnitude and con-consequences of errors in water level indication for shutdown and depressurization following equipment failures that cause high drywell air temperatures, e.g. af ter failure of drywell coolers, or high energy line breaks or leaks inside the drywell.
(3) A conmitment to revise plant operating procedures within 90 days if the analysis of (2) above indicates it is needed to enable the operator to recognize excessive water level errors and to maintain adequate core cooling.
Our review schedule is based on the assumption that the above information will be available for our review by June 1,1982.
If you wish clarification. of the requests or if you cannot meet these dates, please telephone the Licensing Project Manager, G. Edison, within 7 days after receipt of this letter.
Sincerely, OriS nal fignedby:
i Spettswood Eurwell B. J. Youngblood, Chief Licensing Branch No.1 Division of Licensing cc: See next page
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i Mr. Earl A. Borgmann Senior Vice President Cincinnati Gas & Electric Company Post Office Box 960 Cincinnati, Ohio 45201 cc: Troy B. Conner, Jr., Esq.
Deborah Faber Webb Conner, Moore & Corber 7967 Alexandria Pike 1747 Pennsylvania Avenue, N.W.
Alexandria, Kentucky 41001 Washington, D. C.
20006 Andrew B. Dennison, Esq.
Mr. William J. Moran 200 Main Street General Counsel Batavia, Ohio 45103 Cincinnati Gas & Electric Company Post Office Box 960 George E. Pattison, Esq.
Cincinnati, Ohio 45201 Clermont County Prosecuting Attorney 462 Main Street Mr. Samuel H. Porter Batavia, Ohio 45103 Porter, Wright, Morris & Arthur 37 West Broad Street Mr. Waldman Christianson Columbus, Ohio 43215 Resident Inspector /Zinner RFD 1, Post Office Box 2021 Mr. James D. Flynn, Manager U. S. Route 52 Licensing Environmental Affairs Moscow, Ohio 45153 Cincinnati Gas & Electric Company Post Office Box 960 Mr. John Youkilis Cincinnati, Ohio 45201 Office of the Honorable William Gradison David Martin, Esq.
United States House of Representatives-Office of the Attorney General Washington, D. C.
20515 209 St. Clair Street First Floor Timothy S. Hogan, Jr., Chairman Frankfort, Kentucky 40601 Board.of Commissioners 50 Market Street, Clermont County James H. Feldman, Jr., Esq.
Batavia, Ohio 45103 216 East 9th Street l
Cincinnati, Ohio 45220 Lawrence R. Fisse, Esq.
Assistant Prosecuting Attorney l
462 Main Street W. Peter Heile, Esq.
Assistant City Solicitor Batavia, Ohio 45103 Room 214, City Hall Cincinnati, Ohio 45220 Mr. Jam'es G. Keepler I
U. S..IRC, Region III John D. Woliver, Esq.
799 Roosevelt Road Legal Aid Security Glen Ellyn, Illinois 60137 Post Office Box.#47 550 Kilgore Street Batavia, Ohio 45103 l
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